Specific Aspects of HLW-Disposal - Research and Development - The Basis for Safety Assessment and Confidence Building in Radioactive Waste Disposal - Conclusion of the Conference

摘要

Besides the various research topics and the latest results on radioactive waste disposal the REPOSAFE conference provided an excellent overview on the development in countries like France, Sweden, Finland and the USA which are making a strong move towards site identification / qualification for a HLW /SNF repository. As an overall assessment of the ongoing research activities in radioactive waste disposal and to some extent also as an outcome of this conference the following conclusions should be drawn: 1. Disposal techniques for underground emplacement of high-level radioactive waste and spent nuclear fuel have been largely developed and tested, mostly under mock-up conditions. In order to confirm the mature state several research projects within the EU frame program are presently being executed. The future challenge is to test these techniques under 'hot' conditions and adapt/apply them to real waste repositories. 2. Engineered barriers contribute substantially to the long-term safety of repositories in deep geological formations. There are no doubts that, in addition to various conceptual plans and material investigations, the demonstration of the long-term performance has still to be tackled by large scale in situ experiments - as far as possible - under realistic conditions. 3. Safety assessment of HLW/SNF repositories is, in general, still a main task of scientific research. The development and qualification of applicable computer models require an in-depth system understanding which again needs a multidisciplinary data base reflecting most of the long-term processes and material parameters. This kind of research has still to be carried on and will cover, among others, subjects like "natural analoga" in order to validate computer models and to gain greater confidence in long-term predictions.